The invention relates to vibration motors, and in particular, to vibration motors with exposed weights.
In general, an inevitable function for a mobile communication terminal is a call-receiving function. The call-receiving function indicates call-receiving most frequently via a melody mode for producing sound and a vibration mode for shaking the terminal. In other words, if a user previously selects a mode necessary for call-receiving, the selected mode operates at the time of call-receiving to allow the user to detect call-receiving.
In the above call-receiving modes, the vibration mode is generally used for allowing others to keep from noise in a place crowded with people. In general, the vibration mode drives a small-sized vibration motor to transfer a vibrating force to a housing of the terminal, by which the terminal vibrates.
In the meantime, a vibration mode conventionally in use is driven by a vibration motor which is additionally mounted inside the terminal. Examples of the most representative vibration motors include cylinder and pancake types
FIG. 1 depicts a conventional cylinder-type vibration motor 10. The vibration motor 10 comprises a weight 11, a shaft 12, a body 13, and a rubber 14. Since the cylinder-type vibration motor requires larger space for installation, it may not be applied to a minimized mobile phone.
FIG. 2 depicts a conventional pancake-type vibration motor 20. The vibration motor 20 comprises a housing 21, a magnet 22, a rotor 23, a shaft 24, and a weight 23a disposed in the rotor 23. Since the size of the weight 23a is less, the vibrating force of the vibration motor 20 may be weaker.